STUDY DESIGN: Controlled laboratory study using cadaveric knee specimens and a repeated-measures design. OBJECTIVES: To investigate the effect of increased iliotibial band load (assumed to represent increased tensor fascia latae and gluteus maximus strength) on tibiofemoral kinematics and force distribution on the tibiofemoral articulation. BACKGROUND: Owing to the difficulty in measuring in vivo joint loading, there is limited evidence on the direct relationship between increased iliotibial band load and force distribution in the tibiofemoral articulation. METHODS: Eight fresh-frozen cadaveric knee specimens were used in this study. A robotic testing system tested tibiofemoral kinematics under 3 simulated loading conditions: 1) 300 N quadriceps load, 100 N hamstrings load, 0 N iliotibial band load; 2) 300 N quadriceps load, 100 N hamstrings load, 50 N iliotibial band load; 3) 300 N quadriceps load, 100 N hamstrings load, 100 N iliotibial band load. The load distribution in the medial and lateral tibiofemoral articulation was also measured under these loading conditions by using piezoelectric pressure sensors. Data were collected and analyzed at full extension and at 5°, 10°, 15°, 20°, 25°, and 30° of knee flexion. RESULTS: The loads transmitted through the medial tibiofemoral articulation significantly decreased when the load on the iliotibial band was increased with a concomitant significant increase in lateral tibiofemoral articulation load. Increase in the iliotibial band load also increased lateral and anterior tibial translations as well as external and valgus tibial rotations. CONCLUSION: The present study demonstrated that an increase in iliotibial band load when tested in a non-weight bearing condition in a cadaveric model can significantly decrease the loads transmitted through the medial tibiofemoral articulation.
J Orthop Sports Phys Ther, Epub 18 March 2013. doi:10.2519/jospt.2013.4506
KEY WORDS: gluteus maximus, joint forces, knee osteoarthritis, robotic testing system, tensor fascia latae